Aundrea Simmons stands next to her minivan with cases of bottled water she bought after Toledo warned residents not to use its water, Saturday, Aug. 2, 2014 in Toledo, Ohio. About 400,000 people in and around Ohio's fourth-largest city were warned not to drink or use its water after tests revealed the presence of a toxin possibly from algae on Lake Erie.

Toledo Issues Do-Not-Drink Advisory for Tap Water

About 400,000 residents in and around the city of Toledo, Ohio, were warned Saturday not to drink tap water after a toxin was detected in the water supply. Ohio Gov. John Kasich declared a state of emergency for Lucas County and neighboring Wood County, the Ohio Department of Public Safety said in a statement. Chemists at a Toledo water treatment plant recorded readings of microcystin, a highly toxic substance that can cause abnormal liver function, diarrhea and vomiting, according to an advisory. Residents were warned not to drink tap water even after boiling because that could increase the toxin's concentration. Residents can still use the tap water to flush toilets but were warned that children shouldn't bathe in the water and pets shouldn't drink it.

Store shelves in and around Toledo were emptied of bottled drinking water within a few hours. Toledo said it would distribute water supplies to affected residents and asked people not try to scalp or sell water. The toxin, the city said, was likely borne from algal blooms in Lake Erie. Toledo spent roughly $4 million last year in water treatment because of algae concerns and this incident is believed to be the second time in two years a city has issued a do-not-drink advisory because of algae toxins from the lake, The Associated Press reported.